Abstract
In the adult mammalian central nervous system lost nerve cells
are not replaced and there is no regeneration of injured axons in
white matter. Together, these two facts mean there are no
spontaneous reparative mechanisms in operation. Instead, the
adult central nervous system copes with the risks of injuries and
diseases by protective encapsulation in bone, by a multitude of
neuroprotective mechanisms, and finally by the fact that many
important functions are represented by a much larger number of
neurons than minimally needed. The long life expectancy of a
human being nevertheless means that the risk that the central
nervous system is affected by disease, injury or other forms of
insults for which it cannot fully compensate is relatively high.
Experimentally, two strategies are being pursued in order to
develop ways of minimizing various forms of CNS damage, namely
neuroprotective and reparative strategies. Here we present a
possible reparative intervention applicable to spinal cord injury
based on multiple white-to-gray matter peripheral nerve bridge
grafts and work based on the specific role of Nurr1 for dopamine
neuron development, suggesting that development of ligands to
transcription factor might be a new inroad to neuroprotective
treatments in Parkinson's disease.